1. Field of the Invention
The present invention relates generally to raster image-based display technology. More specifically, the present invention relates to a system and method that enhances display rates of raster devices and reduces the quantity of memory needed to display a raster image.
2. Related Art
There are no adequate raster image viewing applications available today to provide, in a single complete package, the necessary capabilities to filly implement an image-based document viewing system. Most applications are too slow to meet display requirements (independent of the hardware platform) and are too cumbersome to use. Additionally, most applications do not support the various raster image formats required, especially CCITT-4 format and numerous and varying strains of TIFF format.
Raster devices failing to meet the display time requirements exhibit three main problems: (1) they require large amounts of RAM to display large raster images; (2) several seconds elapse from the time the raster image is selected for display, to the time the first rows of the raster image are displayed; and (3) the rates at which the raster images are decoded and displayed are too slow. As the size of the raster image increases, the amount of memory required to load and display the image increases. On virtual memory operating systems, large images induce page swapping, which significantly increases the time required to display the image. Some devices perform raster image transformations, such as rotations and mirroring, only on the raster images stored in RAM which sometimes requires several minutes to complete.
Thus, what is required is a raster image device that can generate raster images at a greater speed than current devices, independent of the computer hardware platform. Additionally, what is needed is a raster image device that requires significantly less memory than current raster devices.